It is generally accepted that for resonator applications, the quartz blanks will come from the Z-growth region of a cultured quartz stone. This is because of fewer impurities in the Z-region. Z-seed plates are generally used for the next generation growth of quartz and are usually cut from the Z-region even though the Z-plate could have been cut from any region of a cultured quartz stone. The Z-region is also structurally sounder than any of the other regions of the cultured quartz stone.
However, the dislocations in the Z-region run roughly parallel (within 15.degree.) to Z. Therefore, these dislocations run roughly perpendicular to the Z-plate.